I'm a novice and at a loss to figure out how to open the film holder to insert the film. There are two hooks on the one end that rotate but nothing seems to be coming loose. Any help gratefully appreciated.

The two hooks are there to keep the darkslides in place. It is the darkslides that you want to remove in order to figure out the rest. Move the hooks so that the...bar...they rest across is not covered, then pull on the pull tab on the bar and the slide will pull out...pull it all the way out. Now you will notice that the bottom part of the film holder is hinged and held in place by the darkslide, this hinged piece will now flip open allowing you to insert the film.

Now, when you actually load the film you need only pull the darkslide out about 1/3 of the way, enough to allow the hinged door to open and far enough so that you can be sure you are loading the flim into the film slot and not above the film slot. Since you will be doing this in the dark, or in a bag, you will appreciate not having to try to put the darkslide back in in the dark. Once the film is loaded close the hinged door completely insert the dark slide and make sure the hinged door is secured in place, return the keeper hook at the top so that you dont accidentally pull the slide out.

Additionally, most darkslides are marked in some way, usually on the tab and usually one side is white and one side is black. This is to identify which negatives have been exposed, use whatever logic makes sense to you, (i use white as exposed), so flip the darkslides so that the black side is facing out before you load the films. For this to work you have to remember to flip the darkslide over when you reinsert it after exposure